Various solutions are known for metering liquid media. According to DE 3,324,096 C2, the medium to be applied, in particular, varnish, is metered using a reservoir, a rotating dipping roller, a metering roller, a varnishing cylinder and an impression cylinder. According to DE 3,941,571 A1, a doctor blade can also be assigned to the dipping roller.
EP 0,071,180 A1 discloses a chamber doctor formed essentially by a housing with side walls to which doctor blades, or doctor knives, are fastened. The doctor blades are supported on the applicator roller and the liquid is transferred onto the screened applicator roller via the chamber. The chamber doctor is mounted pivotably in a mounting arranged above the applicator roller and can be advanced onto the applicator roller by means of a working cylinder acting on the mounting.
A disadvantage of these solutions is that, in the case of media having differing viscosity, they do not guarantee an exact metering (that is, production of a specific layer thickness) of the medium to be applied. Therefore, these solutions cannot be used universally to apply onto printing material, media having differing viscosities.
An applicator for printing machines, which is suitable for high-viscosity and low-viscosity media, is disclosed in DE 3,906,648 A1. Metering takes place essentially by means of a profiled scoop roller, doctor blade, transfer roller, smoothing roller or applicator roller, and a form cylinder having cups and a doctor blade.
These versions are complicated in terms of construction, especially when smoothing rollers are used. An object of the invention, therefore, is to develop a solution which eliminates these disadvantages.